The United States on Monday sharply increased the number of countries said to be failing to meet minimum international standards in the fight against human trafficking. Lebanon, Venezuela and several African states are among the new countries given failing grades in the State Department’s annual report on trafficking.

Officials here say that despite greater awareness of the problem, human trafficking around the world continues to grow - propelled, in part, by Internet communications being exploited to lure people into sexual slavery and indentured labor.

As a consequence, the State Department expanded from 13 to 23 its list of so-called Tier 3 countries - states that are not seen as making significant efforts to tackle the problem and could be subject to U.S. sanctions.

At a roll-out event for the global report, covering 184 countries and territories, Secretary of State Hillary Clinton said that as many as 27 million people might be living in slavery. She said that although many countries have anti-trafficking laws, enforcement is lagging.

“The number of prosecutions worldwide has remained relatively static," said Secretary Clinton. "And so the measure of success can no longer be whether a country has passed laws. So many have in the last decade. Now we have to make sure that laws are implemented and that countries are using the tools that have been created for that.”

The report, the 11th issued by the State Department under an anti-trafficking law approved by Congress in 2000, lists several chronic human rights violators as Tier 3 countries - including, Burma, Cuba, Iran, North Korea and Zimbabwe.

U.S. Persian Gulf allies Kuwait and Saudi Arabia remain as Tier 3 states, joined for the first time by, among others, six African states, Lebanon, Turkmenistan, Venezuela and Micronesia.

Of 13 countries listed last year, only one - the Dominican Republic - was removed from Tier 3 for 2011 because of anti-trafficking progress.

The only penalty authorized under U.S. law is the withholding of non-humanitarian aid, and that has been used sparingly.

Clinton said the point of the rating exercise is to encourage countries to respond.

“The report itself is a tool and what we’re most interested in is working with countries around the world and working across our own government to get results," she said. "The decade of delivery is upon us.”

At Clinton’s insistence, the report for the second year in a row assessed human trafficking in the United States, which, like most advanced economies, is placed in Tier 1 with effective laws and enforcement efforts.

But it says the United States remains a source, transit and destination county for men, women and children subjected to forced labor, debt bondage and sex trafficking. It says human traffickers have exploited U.S. visa programs that allow in temporary workers, ostensibly for working in landscaping, farming and tourism industries.

The State Department event honored 10 activists from around the world as heroes, among them Antigua and Barbuda women’s rights advocate Sheila Roseau.

Roseau helped push an anti-trafficking law through the Caribbean country’s legislature last year, which she said is only the starting point in tackling the problem.

“As we recognize the tremendous efforts taken, let us ensure that we continue to advocate for effective support for survivors," said Roseau. "We must continue to be vigilant in all efforts to combat human trafficking by securing the support of our governments to action, the legislative frameworks developed or enact the appropriate legislation if it’s not already in place.”

The report listed six countries as violators of a 2008 U.S. law against the use of child soldiers - Burma, Chad, the Democratic Republic of Congo, Somalia, Sudan and Yemen.

All but Burma receive some U.S. military aid or training. The monitoring group Human Rights Watch called on the Obama administration to end that aid as provided for under the law.